International Journal of Engineering and Applied Sciences (IJEAS) ISSN: 2394-3661, Volume-4, Issue-9, September 2017 Effect of three pollen grains on life table parameters of Neoseiulus californicus (Acari: Phytoseiidae) Maryam Rezaie Abstract— Neoseiulus californicus (McGregor) is a predatory study was to focus on the effect of three pollens (corn pollen, mite that can control spider mites. The effect of different diets date pollen and walnut pollen) on the performance of the such as, corn pollen, walnut pollen and date pollen along with predatory mite N. californicus to mass rearing of this predator the two-spotted spider mite (Tetranychus urticae Koch) eggs on by demographic parameters of this predator on these pollens life table parameters of the predatory mite was determined on with T. urticae. strawberry detached leaves in Petri dishes. The experiments were carried out under laboratory conditions at 27 ± 1°C, 16L: 8D h photo-period and 70 ± 5% RH. Life table parameters were II. MATH analysed based on age-stage, two-sex life table. There was no Colony: The stock culture of T. urticae was maintained on significant difference of total longevity among the different diets. common beans (Phaseolus vulgaris L.) in a growth chamber The fecundity rate on date pollen (14.21±2.92 eggs) was higher (27± 1 °C, 70±5 RH and 16: 8 hours L:D). Neoseiulus than the other diets tested. The intrinsic rate of increase (r) of the predatory mites fed with date pollen (0.201±0.032 day -1) californicus was obtained from ‘Koppert Biological Systems’ was higher than the other treatments. Among the three pollens, and maintained on leaves of common bean, which were date pollen was recognized suitable for development and previously infested with T. urticae. The stock culture of N. reproduction of N. californicus. californicus was maintained in a growth chamber (27± 1 °C, 70±5% RH and 16: 8 hours L:D). Laboratory colonies of N. Index Terms—Life table parameters, Neoseiulus californicus, californicus were reared in the green plastic arenas pollen, spider mite eggs. (18×13×0.1 cm) on water– saturated sponge in a Plexiglas box (25×18×10 cm) that was half-filled with water. The edges I. INTRODUCTION of the arenas were covered with moist tissue paper to provide Neoseiulus californicus (McGregor) (Acari: Phytoseiidae), moisture and prevent predator from escaping. The tested is an important spider mite predator [1], [2]. This predator can pollens were collected by hand (walnut pollen from Tabriz, successfully develop and reproduce on Tetranychus urticae corn pollen from Karaj and date pollen from Bam). Pollens Koch up to 28 generations per year [3]. Neoseiulus were stored in the refrigerator during the experiments. californicus could feed on other pest mites, small insects and Experiments:Gravid female of the predatory mites were even plant pollen [4]. Some researchers studied about the transferred from the main culture onto strawberry leaves effect of different types of food on biological parameters of (cultivar: Gaviota) and left for 24 hours to oviposit. Only one N. californicus [5-9]. egg remained on each leaflet and the mite and additional eggs Some of phytoseiid mites utilize pollen as a food source, were removed. The leaflet of strawberry leaves (2 × 2 cm2) they develop and reproduce on a pollen diet as well [10], was placed upside down on water saturated cotton in a 6 cm [11]. The nutritional value of pollen varies between plant diameter Pteri dish surrounded by strips of wet cotton wool to species and thus the developmental periods and reproductive prevent the mites from escaping. Leaves were provided with response of phytoseiid mites on different pollens can also be sufficient amount of each plant pollen and T. urticae eggs quite variable [12], [13]. Pollen can be used as a food source separately and replaced with them daily. When an individual for mass rearing or to improve predator efficacy in the field. developed to the adult stage, it was paired with an individual Several studies were reported the influence of pollen on life of the opposite sex to obtain the cohort individuals. The history of some phytoseiid mites i.e. ice plant pollen on duration of developmental stages of the predator was Euseius mesembrinus (Dean) [14]; date pollen on recorded at 24-hour intervals. The oviposition rate of N. Proprioseiopsis asetus (Chant) [15]; Oak (Quercus californicus was recorded daily. Each test was continued until virginiana) pollen on Amblyseius largoensis (Muma) [16]; all individuals died and for each diet 70–100 individuals were pollen of cumbungi, Typha orientalis Presl on Amblyseius tested. victoriensis (Womersley) and Typhlodromus doreenae Statistical analysis: Developmental times of all Schicha [17] and cattail pollen on Typhlodromips swirskii individuals, including male and female and those who died (Athias-Henriot) [18], tea pollen on Amblyseius sojaensis before adult stage and female daily fecundity were subjected Ehara [19], Friut tree pollen on Euseius stipulates to analysis of variance. The life tables of the predator were (Athias-Henriot) [20], 21- type plant pollens on T. swirski constructed based on two- sex life table [22]. The population [21]. parameters were estimated based on Chi & Liu’s model [23], In this study, we compared the effects of three pollens as using data of both sexes and the variable developmental rate supplementary food sources on life history and intrinsic among individuals. The population parameters (r (intrinsic r population growth rate of N. californicus. The aim of this rate of increase), λ (finite rate of increase; λ = e ), R0 (net reproduction rate), and T (the mean generation time) were Maryam Rezaie, Zoology Research Department, Iranian Research calculated using TWO SEX-MSChart program [22]. Institute of Plant Protection, Agricultural Research, Education & Extension Developmental times, adult life span and fecundity rates were Organization, Tehran, Iran 21 www.ijeas.org Effect of three pollen grains on life table parameters of Neoseiulus californicus (Acari: Phytoseiidae) analyzed using ANOVA [24]. The mean generation time was mortality was on date pollen (26%). The duration of different defined as the duration that a population needs to increase to life stages of N. californicus fed on three pollens is shown in R0- fold of its size to reach stable age distribution and stable Table 1. increase rate. Intrinsic rate of increase was estimated using the The egg incubation period of N. californicus varied between iterative bisection method from the Euler-Lotka formula with 1.84-1.89 days. Development of N. californicus immature age indexed from 0 [25]. period varied between 2.23 to 2.40 days. The male and female Bootstrap technique was used to estimate variances and longevity of N. californicus was not significantly different on standard errors of the population parameters. In our study, the tested pollens. 10000 replications were used [26], because bootstrapping In addition, the duration of total life span of N. californicus uses random re-sampling and if a small number of replications did not indicate any significant difference among the tested were used, it would result in variable means and standard pollens. Total fecundity of the predatory mite fed on date errors which could end up in unreliable results. Multiple pollen (14.21±2.29 eggs/ female) was higher than that comparison tests among treatments were conducted in observed on the other treatments. Kruskalmc program. The sex ratio of N. californicus was female biased (on corn pollen 70%, date pollen 70%, walnut pollen 61%). The adult III. HELPFUL HINTS preoviposition period (APOP) and total preoviposition period Neoseiulus californicus was able to develop and (TPOP) did not show any significantly different. reporoduce when fed on three diets (date pollen+ egg of T. The analysis of the life table parameters of N. californicus urticae, walnut pollen + egg of T. urticae and corn pollen + indicated the significant difference among the tested pollens egg of T. urticae). The most eggs used in this study (Table 2). The individual fed on date pollen had the highest successfully hatched (85%, 86% and 84% when fed on corn intrinsic rate of increase. In addition, the mean generation pollen, date pollen and walnut pollen plus T. urticae eggs time of predatory fed on different pollens did not show any respectively. The highest mortality at the immature stages was significant difference. on corn pollen (29%) and the lowest immature stages Table 1. Life history statistics (Mean ± SE) of Neoseiulus californicus on different plant pollens and Tetranychus urticae eggs. Developmental time Corn pollen & Date pollen & Walnut pollen & df F P spider mite spider mite spider mite Egg 1.86±0.30 1.84±0.30 1.89±0.37 145 0.38 0.68 Larva & nymph 2.40±0.38 2.25±0.24 2.23±0.37 99 2.40 0.10 Adult longevity Female 13.04±4.29 13.31±3.03 12.56±2.35 66 0.24 0.79 Male 9.17±4.26 9.30±4.76 8.91±3.67 30 0.02 0.97 Preoviposition period APOP† 1.77±0.80 1.31±0.64 1.35±0.86 66 2.75 0.07 TPOP†† 6.05±1.10 5.46±0.81 5.56±0.79 66 2.98 0.06 Lifetime fecundity 4.96±3.75 5.72±3.64 4.75±3.34 171 1.04 0.35 Lifetime longevity 10.61±4.73b 14.21±5.92a 12.06±3.44b 66 3.47 0.04 Means within a row followed by the same letter are not significantly different at the 5% confidence level according to ANOVA test. †APOP (Preoviposition period of female) ††TPOP (Total preoviposition period of female counted from birth) Table 2. Mean ± SE of life table parameters of Neoseiulus californicus on different plant pollens and Tetranychus urticae eggs Life table parameters Plant pollens Mean ± SE CI Date pollen Walnut pollen Intrinsic rate of increase (r) Corn pollen 0.152±0.023 (8.324-0.142)* (-5.821-2.621)n.s.